Mechanical roasting furnace



Oct. 20, 1925 1,558,207

G. STOHN MECHANICAL ROASTING FURNACE Fld Jan. 26. 1921 /nuenfan Patented @en v.20, 1925..

GEORG STOELEN, 0F SEGLBERG, GERMANY.

Il/[ECHANXCL RQiQ-TING EURNACE.

Application filed January 26, 192i.

To all 'whom t may concern.'

Be it linoivn that l, bGaone Sirens, citizen of the flern'ian Republic, and residing Stolberg, Rheinland, Germany, have invent-ed certain nenY and useful improvements in a lllechanical Roasting Furnace {for which l have application for patent4 in Germany October 20, i919), of which the fo.lloc/'ingv is specification.

rEhe invention relates to a mechanical furnace for roasting ores and more particularly to the type, which is known as the Spirlet furnace having several supcrposed roasting chambers, each of them consisting of a stationary and a rotary hearth-plate, the latter being rot-ated from Jthe periphery. ln the known roasting furnaces of this hind a vertical shaft is provided, from which the movement of all the movable hearth-plates is derived. rlhis manner of operation, which obviously necessitates all the hearths to be Worked uniformly, has shown such drawbacks in practice, that the economical working of the furnace has been rendered impossible.

This difficulty is overcome by the present invention; it consists in providing the rotary hearth plates with separate driving devices, so that the same may be moved independently of each other. rlhis manner of operating the rotary hearth-plates and therefore the chambers of the furnace separately and independently leads to a perfect. control and regulation of the furnace and to a far better metallurgical eX- ploitation, than hitherto has been. obtainable. rlhe invention affords a perfect independence in the Working of the various parts of the furnace.

it is for instance possible to employ for any chamber at any time a desired speed of rotation; moveover the direction of rotation may be chosen as required, that is forward or backrvard rotation may bc used.

ln the working of the known furnaces of this hind it happens often, that the ore accumulates at certain points of the furnace lf the speed of rotation of the individual chambers is properly adjusted, as may be easily done by the present invention, accumulations will not occur, as thethichness of the ore layers in all the iloors may be readily chosen as high as required. Such accumulations have hitherto most unfavorably influenced the eliiciency of the furnace, as the speed of rotation had to be chosen Serial No. 440,231.

so small to enable the rabbles to control cinciently the conveyance ofthe ore at such points.

By regulating the speed it is also possible control the operation in each chamber according to the varying condition of the ore. Sometimes it may be necessary to temporarily stop one or more chambers, if for an instance the charging device does not work uniformly.

ilinother hind of regulation may be required, if the ore is to be retained for a longer period witl'iin a certain chamber, for instance if the ore for the purpose of thorough roasting is to be subjected for a longer time to the temperature of the heated hearth. ln such a case the invention makes it possible to cause a. certain chamber to more forward and backward by using a suitable reversing gear.'

The invention is particularly advantageous as regards the metallurgical Working of the furnace. As the invention enables the Working of the furnace to be adjusted in accordance with the changing condition of the ore, the roasting is improved both as regards quantity and quality. The higher elliciency is chiefly due to the fact, that the most favorable height of the layer of the ore, the highest possible speed of feed and the periodical change of direction of the rotation, may be attained quite independently in the various hearths.

its regards the life of 'the furnace, the invention also )resents considerable advantaees, as the durability of the 1abbles,vvhich are inserted in the hearth-plates, is increased owing to the fact, that the layers of the ore may be maintained a uniform thickness.

1One construction illustrating the invention is shown diagrammatically in the accompanying drawings, of which Fig. l is a. vertical section and `iFig. 2 a top view of Fig. i..

The roasting chambers a, al, a2, as, a, (1,5., a, a? consists of a fixed hearth-plate c and a rotating hearth-plate cl; rabble-stones z' are inserted in both of them. rlhe hearthplates carry troughs f and shields e at the outside, vfhich shields enter into the troi z the latter are filled with a suitable scarica' n'laterial, for instance sand,

Each of the hearth-plates o? is fitted with a. toothed ring .6. The pinions h engage with the toothed rings Z; the pinions 7L are mounted on shafts lu, which are driven in :my desired manner. There is always one driving;` mechanism b appliedv to each rotating hearth. To support the rotating hearth-plates rollers r are provided at lhe out-side or' the hearth-plaies (Z, the rollers heilig,` guided on rails s.` The ore is Jfed through the opening' g into the upper Chamher aV and transported hy the rahhles i through the. openings g1 into the second chamber al and so on to the chamber n?, from where it is finally discharged.

l Claim:

l. Mechanical rozisting` furnace having :i series of superposed roasting chambers, each consisting' of a. stationary hearth-platennd e rotating hearth-pleite, rotatedlroin the periphery, the individual rotary hearth-plates being operated h if separate and independent driving means.

linlechenical roasting furnace having .1 series of super-posed roasting` chambers, euch eensisting of :i stationary und a rotary hearth plante. the individual rotary hearthpletes being; operated by separe-ie und indepeneent .lrifingl ineens. the latter heilig; proi vided with ai reservinUV gear for forward .find backwards rotation or the hearth.

ln testirnnny whereof l afiixiny signature.

GEORG STOHN.. 

